Such a process is described e.g. in FR 3010428 A1. This document discloses a method for producing a resilient floor covering comprising a multilayer structure including a transparent wear layer, preferably consisting of polyvinylchloride (PVC) and/or polyurethane (PU) and/or a polyolefin, and a support layer consisting of a thermoplastic resin, preferably a polyvinylchloride (PVC) and/or polyolefin resin. A decorative layer is digitally printed onto the top surface of the support layer or the bottom surface of the wear layer using an inkjet printer operated with a solvent-free ink that can be cured by energy supply. This solvent-free ink layer is then cured by energy supply, in particular by UV radiation. At least one connecting layer, which consists of an emulsion of acrylic or urethane and/or an acrylic copolymer, is bonded to the cured solvent-free ink layer. This connecting layer serves as a connection between the cured solvent-free ink layer and the underside of the wear layer or the upper side of support layer. Indeed, a cured solvent-free ink layer is—according to the teaching of FR 3010428 A1—not chemically compatible with preferred polymer support layers and/or preferred polymer wear layers in a multilayer resilient floor covering, so that laminating such a cured solvent-free ink layer directly between such functional layers of the resilient floor covering would result in a rapid delamination of the resilient floor covering. Therefore, FR 3010428 A1 proposes to cover the cured decorative layer on the support layer, respectively the wear layer, with a connecting layer that is chemically compatible with the cured solvent-free ink layer and the wear layer, respectively the support layer, to which it is to be connected in the resilient floor covering.
A general object of the present invention is to simplify production of a resilient floor covering with a decorative layer that is printed with a solvent free ink.
A more specific object underlying the present invention is to achieve a durable adhesion between a polymer support layer, a transparent polymer wear layer and a decorative layer that is printed with a UV curable ink and sandwiched between the support layer and the wear layer, without having to use an auxiliary connection layer as disclosed in FR 3010428 A1.